a. Field of the Invention
The present invention relates to an electrically remote-controlled mirror assembly for automobiles, and more particularly to a mirror driving apparatus in which the mirror is tilted for a predetermined time or through a predetermined angle from its initial position, especially to check for any obstacle behind the car in a wide rear field of view, and thereafter returned to its initial position.
b. Prior Art Statement
FIGS. 1 and 2 show a prior-art electrically remote-controlled mirror having a side-mirror driving apparatus arranged to adjust the angulation of the mirror by remote control.
FIG. 1 is a plan view of the side-mirror mirror driving apparatus having the mirror body 3 supporting the mirror removed, the drive unit casing 1 being shown as partially fragmented. FIG. 2 is a sectional view of the side-mirror assembly having the mirror body 3 mounted in place, a part of the mirror 4 being omitted for the simplicity of illustration.
FIG. 1 uses axes X-X' and Y-Y' for the convenience of illustration and explanation. There is provided in a position corresponding to their intersection O a ball-and-socket joint 2 on which the mirror body 3 is tiltably supported.
Plungers 5a and 5b are provided on the axes X-X' and Y-Y', respectively, for tilting the mirror body 3 about the vertical and horizontal axes, respectively. Each of the plungers 5a and 5b has a ball portion 6 provided at the end thereof as shown in FIG. 2. The ball portion 6 is fitted in recess formed in the rear side of the mirror body 3 to form a ball-and-socket joint. The plunger has an external thread formed on the outer circumference thereof and also a recess 7 formed axially in a part of the outer circumference. Each of reduction gear trains 11a and 11b is formed by a plurality of gears including a final gear 9a (9b) which is in mesh with the external thread of each plunger 5a (5b). The recess 7 receives a projection 8 provided on the drive unit casing 1. Thus each plunger is blocked against pivoting about the axis thereof, so the rotation of a motor 10a (10b) is converted into an axial movement of each plunger 5a (5b) through the last gear 9a (9b) of the reduction gear train 11a (11b). As the plunger 5a or 5b is moved axially, the mirror 4 tilts about the vertical or horizontal axis.
The adjustable range of the angulation of the mirror 4 is set for a field of vision required when the car moves normally on the road. The angulation speed is so set that the mirror angulation can be adjusted with an accuracy required in practice. If the mirror 4 is tilted too quick, a desired angulation cannot easily be attained.
However, in a special driving condition such as when moving the car back near the road edge or moving the car in the direction of its width by repeating forward and backward movement, it is desired to use the mirror for checking for any obstacle or the like near the rear wheel. For this purpose, it is necessary to quickly tilt down the mirror further through a predetermined angle from the angular position of the mirror in normal drive of the car.
In these circumstances, a side-mirror driving apparatus is desirably provided by which the mirror can be quickly tilted down through a predetermined angle for having a rear view toward the rear wheel and thereafter tilted back to its initial position for normal moving of the car. One of the mirror driving apparatuses of this type is disclosed in the U.S. Pat. No. 4,632,525. This apparatus comprises at least one lever or threaded rod having a longitudinal axis disposed in a casing and swingably linked to a rear surface of the mirror at one end thereof, and at least one driving means drivingly connected to the lever for reciprocating the lever along with the axis thereof so as to incline the mirror. The driving means includes a first rotating member rotatably held on the casing, a first motor for rotating the first rotating member, and a second rotating member rotatably and movably coupled to the casing in such a manner that the second rotating member reciprocates along with the axis of the lever. The first rotating member is connected to the second rotating member connected to the second rotating member in such a manner that the rotation of the first rotating member is transmitted to the second rotating member. A linkage means is drivingly so connected between the second rotating member and a second motor that the rotation of the second motor makes the second rotating member reciprocate along with the axis of the lever, and a driving connection means is drivingly so connected between the lever and the second rotating member that at least one of the rotation and the reciprocation of the second rotating member makes the lever reciprocate along with the axis of the lever.
In this side-mirror driving apparatus, the side mirror is inclined by a predetermined angle to confirm an obstacle behind the car by reciprocating the second rotating means along the axis of the lever or threaded rod by means of the linkage means which is driven by the second motor. In this state, the lever or threaded rod is reciprocated together with the second rotating member.
In the above-mentioned side-mirror driving apparatus, many components are housed in the casing. Particularly the plurality of link levers and gears forming the linkage means must be drivingly connected between the second rotating member and second motor. Thus assembling of them into the casing needs much labor and the adjustment of them is very complicated. Since the components of the linkage means are disposed apart from the axis of the lever or threaded rod, it is difficult to design a compact and thin casing.